During March
2000 Rudi Strickler visited the laboratory of Yuji Tanaka in Tokyo for
one week. Yuji organized the use of a high-speed video camera and took
the following clip.Each
frame had an exposure time of 1 msec. There were 250 frames per second.
One cycle of the pumping movement of the Daphnia was about 360 msec long.
Here we took 21 frames at a time interval of 1/60 sec. We cleaned them
up in Adobe Photoshop and saved them as GIF files. Then we exposed each
of them for 1/10 sec in an animated GIF.

MOTION
AT 250 FPS

Observe
the motion of the second and third limb (counting from the left = head).
They act like wings, sucking water in-between them from the feeding current
and pushing it out on its way through the carapace.